The present invention relates to a numerous user laser communications
optical system. Numerous optical signals comprising a number of channels
are simultaneously received and demultiplexed (and/or multiplexed and
transmitted) at a numerous access communication device. The numerous
access communication device may comprise multiple stages that each
include a multiple order waveplate and a polarizing beam splitter. The
multiple order waveplate is configured so that it retards a first
electrical field component of signals corresponding to certain channels
in a frequency grid in an integer multiple of wavelengths with respect to
a second electrical field component, and retards a first electrical field
component of signals corresponding to other channels in the frequency
grid in an integer multiple of wavelengths plus one-half a wavelength
with respect to a second electrical field component. Separation can then
be performed on the basis of the resulting opposite polarization.